Reticle carrier and associated methods

ABSTRACT

A reticle carrier described herein is configured to quickly discharge the residual charge on a reticle so as to reduce, minimize, and/or prevent particles in the reticle carrier from being attracted to and/or transferred to the reticle. In particular, the reticle carrier may be configured to provide reduced capacitance between an inner baseplate of the reticle carrier and the reticle. The reduction in capacitance may reduce the resistance-capacitance (RC) time constant for discharging the residual charge on the reticle, which may increase the discharge speed for discharging the residual charge through support pins of the reticle carrier. The increase in discharge speed may reduce the likelihood that an electrostatic force in the reticle carrier may attract particles in the reticle carrier to the reticle. This may reduce pattern defects transferred to substrates that are patterned using the reticle, may increase semiconductor device manufacturing quality and yield, and may reduce scrap and rework of semiconductor devices and/or wafers.

BACKGROUND

A lithography mask, such as a photomask or a reticle, may be used in anexposure tool (e.g., a scanner or a stepper) to form a pattern on asubstrate. The pattern may be developed such that the pattern can beused to form semiconductor structures and/or devices on the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 is a diagram of an example semiconductor processing environmentdescribed herein.

FIGS. 2A and 2B are diagrams of an example reticle carrier describedherein for use in the semiconductor processing environment of FIG. 1 .

FIGS. 3, 4A, and 4B are diagrams of example implementations of thereticle carrier of FIGS. 2A and 2B described herein.

FIGS. 5A-5K are diagrams of an example implementation described herein.

FIG. 6 is a diagram of example components of one or more devices of FIG.1 .

FIG. 7 is a flowchart of an example process relating to transferring areticle to a reticle carrier described herein.

FIG. 8 is a flowchart of an example process relating to forming areticle carrier described herein.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

A reticle (or another type of lithography mask) may be secured to areticle stage of an exposure tool by an electrostatic clamp. After anexposure operation, the reticle may be removed from the reticle stageand placed in a reticle carrier. The reticle may be transported in thereticle carrier, which may be sealed to reduce and/or minimize ingressof humidity, oxygen, and/or particles (e.g., dust, debris, and/or otherforeign objects) from damaging the reticle.

A reticle that is placed in a reticle carrier may have a residual chargethat remains on the reticle after discharge of the electrostatic clamp.The residual charge may attract particles in the reticle carrier ontothe reticle because of the difference in charge between the lithographymask and the mask stage. The particles may affect the pattern that istransferred from the reticle to a substrate. This can have significantimpacts on semiconductor device manufacturing quality and yield, as anypattern defects may be repeatedly transferred to hundreds or thousandsof substrates, which can lead to waste and additional semiconductordevice manufacturing to replace the defective semiconductor devices.

Some implementations described herein provide reticle carriers, methodsof use, and methods of formation. In some implementations, a reticlecarrier described herein is configured to quickly discharge the residualcharge on a reticle so as to reduce, minimize, and/or prevent particlesin the reticle carrier from being attracted to and/or transferred to thereticle. In particular, the reticle carrier may be configured to providereduced capacitance between an inner baseplate of the reticle carrierand the reticle. The reduction in capacitance may reduce theresistance-capacitance (RC) time constant for discharging the residualcharge on the reticle, which may increase the discharge speed fordischarging the residual charge through support pins of the reticlecarrier. The increase in discharge speed may reduce the likelihood thatan electrostatic force in the reticle carrier may attract particles inthe reticle carrier to the reticle. This may reduce pattern defectstransferred to substrates that are patterned using the reticle, mayincrease semiconductor device manufacturing quality and yield, and mayreduce scrap and rework of semiconductor devices and/or wafers.

FIG. 1 is a diagram of an example semiconductor processing environment100 described herein. The semiconductor processing environment 100 mayinclude an environment in which substrates, such as semiconductorwafers, semiconductor devices, reticles, photomasks, and/or othercomponents in a semiconductor fabrication facility, are processedthrough exposure operations to form pattern on the substrates forfurther processing in the semiconductor fabrication facility.

As shown in FIG. 1 , the semiconductor processing environment 100 mayinclude an exposure tool 102, a load port 104 on which a reticle carrier106 may be positioned and/or supported, an interface tool 108, and aload lock chamber 110 connecting the exposure tool 102 and the interfacetool 108.

The interface tool 108 may be configured to transfer reticles betweenthe load port 104 and the exposure tool 102. The interface tool 108 mayinclude an equipment front end module (EFEM) or similar type ofinterface tool that is situated between the load port 104 and theexposure tool 102. The interface tool 108 may include a chamber 112 thatis sealed from the external environment of the semiconductor processingenvironment 100 to reduce and/or minimize contamination of reticles thatare transferred through the interface tool 108.

The interface tool 108 may further include a reticle transport device114 in the chamber 112. The reticle transport device 114 may include arobotic arm or another type of tool that is configured to transportreticles between the reticle carrier 106 and the exposure tool 102through the load lock chamber 110. The load lock chamber 110 may includea chamber that is configured to permit the transfer of reticles betweenthe interface tool 108 and the exposure tool 102 while maintainingenvironmental isolation between the interface tool 108 and the exposuretool 102.

The exposure tool 102 is a semiconductor processing tool that is capableof exposing a photoresist layer on a substrate to a radiation source,such as an ultraviolet light (UV) source (e.g., a deep UV light source,an extreme UV (EUV) light source, and/or the like), an x-ray source, anelectron beam source, and/or another type of radiation source. Theexposure tool 102 may expose a photoresist layer to the radiation sourceto transfer a pattern from a reticle (or a photomask) to the photoresistlayer. The pattern may include one or more semiconductor device layerpatterns for forming one or more semiconductor devices on the substrate,may include a pattern for forming one or more structures of asemiconductor device on the substrate, and/or may include a pattern foretching various portions of a semiconductor device and/or the substrate,among other examples. In some implementations, the exposure tool 102includes a scanner, a stepper, an immersion lithography tool, an EUVlithography tool, or a similar type of exposure tool.

The exposure tool 102 may include a chamber 116 and a reticle transportdevice 118 in the chamber 116. A vacuum (or an ultra-high vacuum) may bemaintained in the chamber 116 so that EUV exposure operations may beperformed. The reticle transport device 118 may include a robotic arm oranother type of tool that is configured to transport reticles betweenthe exposure tool 102 and the load lock chamber 110. The exposure tool102 may further include a cover rack 120 that is configured to supportand/or secure an internal cover of the reticle carrier 106 while areticle associated with the reticle carrier 106 is in use in theexposure tool 102. The reticle transport device 118 may position aninternal cover of the reticle carrier 106 on one or more support membersof the cover rack 120 to access the reticle associated with the reticlecarrier 106.

The exposure tool 102 may include an exchanging station 122 configuredto support and/or secure an inner baseplate of the reticle carrier 106and the reticle associated with the reticle carrier 106. The exchangingstation 122 may be further configured to move to various locationswithin the chamber 116 to position the reticle for securing to a reticlestage 124 of the exposure tool 102, to position the inner baseplate forretrieval of the reticle from the reticle stage 124, and/or to positionthe reticle and the inner baseplate for retrieval by the reticletransport device 118.

The reticle stage 124 may include an electrostatic chuck that isconfigured to secure the reticle in place for an exposure operation byan electrostatic clamp. The reticle stage 124 may form the electrostaticclamp by generating an electric potential (or an electrostatic field)between the reticle stage 124 and the reticle. The electric potentialsecures the reticle to the reticle stage 124. The reticle stage 124 mayrelease the electrostatic clamp so that the reticle may be returned tothe reticle carrier 106, and so that another reticle may be placed onthe reticle stage 124 for another exposure operation.

In some implementations, the exposure tool 102 includes additionalcomponents to those shown in FIG. 1 . For example, the exposure tool 102may include an immersion lithography tool that operates in a deep UVspectrum, and may include a system of transmissive lenses that isconfigured to collimate, focus, collect, filter and/or direct UVradiation from a radiation source through a reticle or photomask andtoward a substrate. As another example, the exposure tool 102 mayinclude an EUV lithography tool that operates in an EUV spectrum, andmay include a system of reflective mirrors that is configured tocollimate, focus, collect, filter and/or direct UV radiation from aradiation source off of a reticle or photomask and toward a substrate.

As indicated above, FIG. 1 is provided as an example. Other examples maydiffer from what is described with regard to FIG. 1 .

FIGS. 2A and 2B are diagrams of an example reticle carrier 106 describedherein for use in the example semiconductor processing environment 100of FIG. 1 . In some cases, a residual charge may remain on a reticlefrom the electrostatic clamp that is used to secure the reticle to thereticle stage 124 (e.g., after the electrostatic clamp is released).Accordingly, the reticle carrier 106 may be configured to quicklydischarge the residual charge on a reticle that is positioned in thereticle carrier 106 so as to reduce, minimize, and/or prevent particlesin the reticle carrier from being attracted to and/or transferred to thereticle.

As shown in FIG. 2A, the reticle carrier 106 may include a housing 202that includes an upper shell 204 and a lower shell 206. FIG. 2Aillustrates an assembled configuration of the housing 202, in which theupper shell 204 is mated or coupled with the lower shell 206. Anoverhead hoist transport (OHT) head 208 may be included on a top portionof the upper shell 204 to permit the reticle carrier 106 to betransported by an OHT vehicle, by an automated material handling system(AMHS), by a reticle stocker, and/or by another automated transportdevice. As an example, a lift of an OHT vehicle may latch onto the OHThead 208 to load the reticle carrier 106 into the OHT vehicle and tosecure the reticle carrier 106 while the reticle carrier 106 istransported in the OHT vehicle. Moreover, the lift of the OHT vehiclemay unlatch from the OHT head 208 to provide the reticle carrier 106 toa location such as a staging area of a reticle storage system or to aload port (e.g., the load port 104) associated with an exposure tool(e.g., the exposure tool 102).

In some implementations, one or more dimensions of the housing 202, theupper shell 204, the lower shell 206, and/or the OHT head 208 may beconfigured to conform to and/or satisfy one or more standardized reticlecarrier dimensional parameters to permit the reticle carrier 106 to betransported by various types of reticle transport devices. The one ormore standardized reticle carrier dimensional parameters may include oneor more parameters of a reticle carrier specification, such as SEMIE100, SEMI E111, and/or SEMI E112. The one or more dimensions mayinclude external dimensions of the reticle carrier 106, such as a lengthdimension (the x dimension in FIG. 2A) of the housing 202, a widthdimension (they dimension in FIG. 2A) of the housing 202, and/or aheight dimension (the z dimension in FIG. 2A) of the housing 202. Theexternal dimensions may be based a particular size of reticle (or arange of sizes of reticles) that the reticle carrier 106 is totransport, such as 6 inch reticles, 150 millimeter reticles, or 230millimeter reticles, among other examples. An example range for thelength dimension (the x dimension in FIG. 2A) may include approximately175 millimeters to approximately 300 millimeters. An example range forthe width dimension (they dimension in FIG. 2A) may includeapproximately 150 millimeters to approximately 230 millimeters. Anexample range for the height dimension (the z dimension in FIG. 2A) mayinclude approximately 26 millimeters to approximately 100 millimeters.However, other values or ranges for the x dimension, they dimension,and/or the z dimension are within the scope of the present disclosure.

FIG. 2B illustrates an exploded configuration of housing 202 in whichthe upper shell 204 and the lower shell 206 are separated to expose aninner space 210 of the reticle carrier 106. The upper shell 204 and thelower shell 206 may be configured to form and enclose the inner space210 when the upper shell 204 and the lower shell 206 are coupled. Asfurther shown in FIG. 2B, the reticle carrier 106 may include an innercover 212 and an inner baseplate 214. The inner cover 212 and the innerbaseplate 214 may be sized and/or otherwise configured to fit within theinner space 210 formed by the upper shell 204 and the lower shell 206.Moreover, the inner cover 212 and the inner baseplate 214 may be sizedand/or otherwise configured to secure or hold a reticle 216, and topermit secure transport of the reticle 216 in the reticle carrier 106.The reticle 216 may include an EUV reticle, an immersion lithographyphotomask, or another type of device on which a lithography pattern isincluded. The lithography pattern may be transferred to a substratethrough reflection of radiation off of the lithography pattern or bytransmission of the radiation through the lithography pattern.

The upper shell 204, the lower shell 206, the OHT head 208, the innercover 212, and/or the inner baseplate 214 may be formed of various typesof materials, including non-conductive materials and/or conductivematerials. In some implementations, the upper shell 204, the lower shell206, the OHT head 208, the inner cover 212, and/or the inner baseplate214 are formed of a plastic or a polymer material. In someimplementations, one or more portions of the upper shell 204, the lowershell 206, the OHT head 208, the inner cover 212, and/or the innerbaseplate 214 are formed of a conductive material that is electricallyconnected to an electrical grounding point to permit a residual chargeon the reticle 216 to be discharged through one or more portions of thereticle carrier 106.

As indicated above, FIGS. 2A and 2B are provided an example. Otherexamples may differ from what is described with regard to FIGS. 2A and2B.

FIG. 3 is a diagram of an example implementation 300 of the reticlecarrier 106 of FIGS. 2A and 2B described herein. The exampleimplementation 300 may include an example in which the reticle carrier106 includes support pins, on which the reticle 216 is to be secured,are configured such that the distance between the inner baseplate 214and the reticle 216 reduces the capacitance between an inner baseplate214 and the reticle 216. The reduction in capacitance may reduce the RCtime constant for discharging a residual charge on the reticle 216,which may increase the discharge speed for discharging the residualcharge through the support pins of the reticle carrier 106. The increasein discharge speed may reduce the likelihood that an electrostatic forcein the reticle carrier 106 attract particles in the reticle carrier 106to the reticle 216 and/or may reduce the size of particles that areattracted to the reticle 216.

As shown in FIG. 3 , the reticle 216 may be positioned within an innerspace 302 formed by the inner cover 212 and the inner baseplate 214. Thereticle carrier 106 may include a plurality of support pins 304 that areconfigured to maintain the reticle 216 off of the inner baseplate 214 inthe inner space 302. The reticle carrier 106 may include additionalsupport members 306 in and/or on the inner cover 212 to secure thereticle 216 in place and to prevent vibration and/or other types ofmovement of the reticle carrier 106 from causing the reticle 216 tocontact the inner cover 212. The inner cover 212 may include a filter308 that is configured to filter the air or gas, that is provided to theinner space 302, of particles and/or other types of contaminants. Theinner baseplate 214 may include a plurality of alignment windows 310that permit the reticle 216 to be properly aligned when securing thereticle to the reticle stage 124.

As shown in a close-up view 312 in FIG. 3 , the reticle 216 may have anegative residual charge when placed in the reticle carrier 106. Theinner baseplate 214 may be maintained at a positive charge. Thedifference in polarity between the reticle 216 and the inner baseplate214 may cause an electric field to be generated between the reticle 216and the inner baseplate 214. The electric field may apply a force toparticles 314 on the inner baseplate 214. The force may attract theparticles 314 toward and onto the reticle 216. The stronger the electricfield is, the stronger the force that is applied to the particles 314.Accordingly, the stronger the electric field, the larger the size ofparticles 314 that may be attracted to the reticle 216.

To reduce the effect of the electric field, the inner baseplate 214 maybe connected to an electrical ground such that the residual charge onthe reticle 216 may be discharged through the support pins 304. However,a capacitive effect between the negatively charged reticle 216 and thepositively charged inner baseplate 214 may slow or reduce the speed ofdischarge of the residual charge from the reticle 216. The capacitiveeffect promotes the storage of charge between the reticle 216 and theinner baseplate 214, which resists the discharge of the residual chargefrom the reticle 216. This increases the RC time constant fordischarging the residual charge, which increases the time duration tofully discharge the residual charge.

Accordingly, the support pins 304 may be configured to facilitatedischarging of a residual charge on the reticle 216 when the reticle 216is placed in the reticle carrier 106. In particular, the support pins304 may be sized such that a distance (d1) between the reticle 216 andthe inner baseplate 214 (e.g., the surface of the inner baseplate 214facing or orientated toward the reticle 216) reduces and/or minimizesthe capacitance between the reticle 216 and the inner baseplate 214. Inthis way, the distance (d1) may be configured to reduce, minimize,and/or prevent the attraction of particles 314 toward the reticle 216that might otherwise be caused by the residual charge on the reticle216.

In the example implementation 300, the distance (d1) may correspond tothe height (h1) of the support pins 304 from the inner baseplate 214 tothe top 316 of the support pins 304. Thus, the greater the height (h1)of the support pins 304 (and thus, the greater the distance (d1)) thelower the capacitance between the reticle 216 and the inner baseplate214 for the same area reticle 216, the same area inner baseplate 214,and the same permittivity between the reticle 216 and the innerbaseplate 214. The lower the capacitance between the reticle 216 and theinner baseplate 214, the quicker the discharge speed of the residualcharge on the reticle 216 through a discharge path 318 through thesupport pins 304. The quicker the discharge speed, the smaller the size(e.g., the smaller the radius (r₁)) of particles 314 that are likely tobe attracted toward the reticle 216. As an example, the height (h1) ofthe support pins 304 may be configured as approximately 200 microns toprevent particles 314 having a radius (r1) equal to or greater thanapproximately 147 nanometers from being attracted to the reticle 216. Asanother example, the height (h1) of the support pins 304 may beconfigured as approximately 400 microns to prevent particles 314 havinga radius (r1) equal to or greater than approximately 75 nanometers frombeing attracted to the reticle 216. As another example, the height (h1)of the support pins 304 may be configured as approximately 1000 micronsto prevent particles 314 having a radius (r1) equal to or greater thanapproximately 22 nanometers from being attracted to the reticle 216. Insome implementations, the height (h1) of the support pins 304 (and thus,the greater the distance (d1)) may be in a range of approximately 1150microns to approximately 4000 microns to provide a sufficientcapacitance decrease while minimizing the increase to the overall weightof the reticle carrier 106 and impact to reticle transport devices 114and 118. However, other values for the distance (d1) and the height (h1)are within the scope of the present disclosure.

In some implementations, the height (h1) of the support pins 304 (andthus, the greater the distance (d1)) may be determined and configuredbased on a model. The model may be used to determine or estimate thedistance (d1) between the inner baseplate 214 and the reticle 216 (andthus, the height (h1) of the support pins 304) such that one or moreparameter thresholds are satisfied. The one or more threshold parametersmay include, for example, a threshold particle size, a capacitancethreshold, an electrostatic force threshold, and/or another thresholdparameter threshold.

In some implementations, a device (e.g., the device 600 described hereinin connection with FIG. 6 ) may determine the threshold particle size toprevent particles 314 equal to or greater than the threshold particlesize from being electrostatically attracted to the reticle 216. Thedevice may use the model to determine the distance (d1) between theinner baseplate 214 and the reticle 216 (and thus, the height (h1) ofthe support pins 304) such that capacitance threshold for a capacitancebetween the inner baseplate 214 and the reticle 216 is satisfied. Inthis way, the device may determine the capacitance, using the model,such that the capacitance is low enough to quickly discharge theresidual charge on the reticle 216 so as to prevent particles 314 equalto or greater than the threshold particle size from beingelectrostatically attracted to the reticle 216.

The model may include an electrostatic force threshold for attractingparticles 314 equal to and/or greater than the threshold particle sizeto the reticle 216. The device may determine the electrostatic forcethreshold based on:

F _(E) =Q _(induced) E(t)

where Q_(induced) corresponds to the magnitude of the residual charge onthe reticle 216 and E (t) is the electric field magnitude of anestimated electric field (which may be time-varying during dischargingof the residual charge) between the inner baseplate 214 and the reticle216. The device may determine the electric field magnitude based on:

${E(t)} = \frac{V(t)}{d}$

where V(t) corresponds to an electric potential (which may betime-varying during discharging of the residual charge) between theinner baseplate 214 and the reticle 216 and d corresponds to thedistance (d1) and the height (h1). The device may determine the electricpotential based on:

${V(t)} = \frac{Q(t)}{C}$

where Q (t) corresponds to the time-varying residual charge (which maybe referred to as a discharge rate parameter) on the reticle 216 and Ccorresponds to the capacitance between the inner baseplate 214 and thereticle 216. The device may determine the time-varying residual chargebased on:

${Q(t)} = {Q_{0}\frac{- t}{e^{R_{Support}C}}}$

where Q₀ corresponds to the initial magnitude of the residual chargeprior to discharging, R_(Support) corresponds to the resistance of thesupport pins 304, and C corresponds to the capacitance between the innerbaseplate 214 and the reticle 216. The resistance of the support pins304 (R_(Support)) and the distance (d1) and the height (h1) correspondto the RC time constant between the inner baseplate 214 and the reticle216.

Based on the relationships defined above, the device may determine theexponential decay of the residual charge based on the resistance of thesupport pins 304 (R_(Support)) and the distance (d1) and the height (h1)to satisfy a particular discharge rate parameter associated with thereticle 216. In particular, the device may determine the distance (d1)and the height (h1) to increase or decrease the RC time constant, andthus the rate of exponential decay of the residual charge, tocorrespondingly increase or decrease the time-varying electric potentialand the time-varying electric field magnitude to satisfy theelectrostatic force threshold. Accordingly, the greater the distance(d1) and the height (h1) determined by the device, the lesser theelectrostatic force that is to be applied to particles 314 in thereticle carrier 106, which reduces the size of particles 314 that areattracted to the reticle 216.

As indicated above, FIG. 3 is provided an example. Other examples maydiffer from what is described with regard to FIG. 3 .

FIGS. 4A and 4B are diagrams of an example implementation 400 of thereticle carrier 106 of FIGS. 2A and 2B described herein. The exampleimplementation 400 may include an example in which the reticle carrier106 includes a recessed region in a portion of the inner baseplate 214.The recessed region results in the distance between the reticle 216 andthe inner baseplate 214 being greater in the portion of the innerbaseplate 214 that includes the recessed region. The increased distanceprovided by the recessed region reduces the capacitance between an innerbaseplate 214 and the reticle 216. The reduction in capacitance mayreduce the RC time constant for discharging a residual charge on thereticle 216, which may increase the discharge speed for discharging theresidual charge through the support pins of the reticle carrier 106. Theincrease in discharge speed may reduce the likelihood that anelectrostatic force in the reticle carrier 106 attract particles 314 inthe reticle carrier 106 to the reticle 216 and/or may reduce the size ofparticles 314 that are attracted to the reticle 216.

As shown in the cross-sectional view in FIG. 4A, the reticle carrier 106may include elements 402-410 in the example implementation 400, whichmay be similar to elements 302-310 in the example implementation 300.However, the inner baseplate 214 of the reticle carrier 106 may includea recessed region 412. The recessed region 412 may be located in aportion of the inner baseplate 214 over which the reticle 216 isconfigured to be positioned. The distance between the inner baseplate214 in the recessed region 412 and the reticle 216 may be greaterrelative to a distance between the inner baseplate 214 in a non-recessedportion 414 and the reticle 216 to decrease the capacitance between theinner baseplate 214 and the reticle 216 (and thus, to increase thedischarge rate of the residual charge on the reticle 216).

As shown in a close-up portion 416 in FIG. 4A, the recessed region 412may be included in the inner baseplate 214 and may have a depth (d2)relative to a top surface of the non-recessed portion 414. The depth(d2) of the recessed region may be in a range of approximately 1000microns to approximately 3500 microns to provide a sufficient dischargerate of the residual charge on the reticle 216 and to minimize theincrease to the overall weight of the reticle carrier 106 and impact toreticle transport devices 114 and 118. However, other values for thedepth (d2) are within the scope of the present disclosure. The thickness(d) of the inner baseplate 214 in the recessed region 412 may be in arange of approximately 5000 microns to approximately 7500 microns toprovide sufficient strength and structural rigidity for the innerbaseplate 214. However, other values for the thickness (t1) are withinthe scope of the present disclosure. The ratio between the depth (d2)and the thickness (t1) of the baseplate in the recessed region may be ina range of approximately 0.13 to approximately 0.7 to provide asufficiently deep recessed region 412 and to maintain sufficientstructural rigidity for the inner baseplate 214. However, other valuesfor the ratio are within the scope of the present disclosure.

As indicated above in connection with FIG. 3 , a device (e.g., thedevice 600 described in connection with FIG. 6 ) may use the model todetermine the distance between the inner baseplate 214 and the reticle216 to satisfy one or more parameter thresholds. Similarly, the devicemay use the model described above to determine the depth (d2) of therecessed region 412 and/or a height (h2) of the support pins 404 (whichmay correspond to a distance (d3) between the inner baseplate 214 in thenon-recessed portion 414 and a top 418 of the support pins 404) suchthat an overall distance (d4) between the inner baseplate 214 and thereticle 216 in the recessed region 412 satisfies one or more parameterthresholds. As an example, the device may determine to increase theheight (h2) of the support pins 404 and/or increase the depth (d2) ofthe recessed region 412 to increase the overall distance (d4), which mayincrease the discharge rate of discharging the residual charge on thereticle 216. In some implementations, the overall distance (d4) is in arange of approximately 1150 microns to approximately 4000 microns toprovide a sufficient capacitance decrease while minimizing the increaseto the overall weight of the reticle carrier 106 and the impact toreticle transport devices 114 and 118. However, other values for theoverall distance (d4) are within the scope of the present disclosure. Inthis way, the device may use the model to satisfy a capacitancethreshold for a capacitance between the inner baseplate 214 and thereticle 216 based on a threshold particle size to satisfy a dischargerate parameter associated with the reticle 216, and/or to satisfyanother parameter or parameter threshold.

As shown in a top-down view in FIG. 4B, the recessed region 412 may beincluded within a perimeter 420 defined by support pins 404 a, 404 b,404 c, and 404 d. Moreover, the recessed region 412 may extend betweentwo support pins, such as between support pins 404 a and 404 b, betweensupport pins 404 a and 404 c, between support pins 404 b and 404 d, andbetween support pins 404 c and 404 d. A width (w1) of the recessedregion 412, that is in between two support pins (e.g., the support pins404 a and 404 b) may be in a range of approximately 130 millimeters toapproximately 140 millimeters so that the recessed region 412 fits inbetween the support pins and provides sufficiently low capacitancebetween the inner baseplate 214 and the reticle 216. However, othervalues for the width (w1) are within the scope of the presentdisclosure. A width (w2) of the recessed region 412, that is not inbetween two support pins (e.g., the support pins 404 a and 404 b) may bein a range of 140 millimeters to approximately 155 millimeters so thatthe recessed region 412 fully extends to the outside edges of thesupport pins and provides sufficiently low capacitance between the innerbaseplate 214 and the reticle 216. However, other values for the width(w2) are within the scope of the present disclosure.

As indicated above, FIGS. 4A and 4B are provided an example. Otherexamples may differ from what is described with regard to FIGS. 4A and4B.

FIGS. 5A-5K are diagrams of an example implementation 500 describedherein. The example implementation 500 may include an example oftransferring the reticle 216 from the reticle stage 124 to the reticlecarrier 106.

As shown in FIG. 5A, the reticle 216 may be secured to the reticle stage124, which may include an electrostatic chuck. The reticle 216 may besecured to the reticle stage 124 by an electrostatic clamp, whereopposing charges on the reticle 216 and on the reticle stage 124 attractthe reticle 216 toward the reticle stage 124. The exposure tool 102 mayperform an exposure operation in which the reticle 216 is used totransfer a pattern of the reticle 216 to a substrate as part offormation of one or more semiconductor devices on the substrate. Asfurther shown in FIG. 5A, the inner baseplate 214 of the reticle carrier106 may be positioned on the exchanging station 122 in preparation forreceiving the reticle 216. The inner cover 212 may be positioned in oneof the slots of the cover rack 120.

As shown in FIG. 5B, the exposure tool 102 may move the exchangingstation 122 to position the inner baseplate 214 under the reticle 216.For example, the exposure tool 102 may move the exchanging station 122to position the inner baseplate 214 under the reticle 216 after theexposure operation to exchange out the reticle 216 (e.g., for anotherreticle). With the inner baseplate 214 positioned under the reticle 216,the exposure tool 102 may release the electrostatic clamp between thereticle stage 124 and the reticle 216. This causes the reticle 216 to beno longer secured to the reticle stage 124 and, instead, supported onthe inner baseplate 214. In particular, the reticle 216 may be supportedon the plurality of support pins (e.g., the support pins 304 and/or 404)included on the inner baseplate 214.

As described above, a residual charge may remain on the reticle 216after release of the electrostatic clamp. Accordingly, the residualcharge may begin to be discharged through the plurality of support pinswhen the reticle 216 is positioned on the plurality of support pins. Thedistance (d1, d4) between the reticle 216 and the inner baseplate 214may be configured, as described above in connection with FIG. 3 or FIGS.4A and 4B, to reduce, minimize, and/or prevent the attraction ofparticles 314 of a particular size from the inner baseplate 214 of thereticle carrier 106 to the reticle 216. As an example, the distance (d1,d4) between the reticle 216 and the inner baseplate 214 may beconfigured, as described above in connection with FIG. 3 or FIGS. 4A and4B, to reduce, minimize, and/or prevent the attraction of particles 314equal to or greater than a threshold particle size.

As shown in FIG. 5C, the exposure tool 102 may lower or otherwise movethe exchanging station 122 toward the cover rack 120. As shown in FIG.5D, the reticle transport device 118 may move toward the exchangingstation 122 and may retrieve the reticle 216 on the inner baseplate 214from the exchanging station 122.

As shown in FIG. 5E, the reticle transport device 118 may position theinner baseplate 214, with the reticle 216 positioned on the innerbaseplate 214, under the inner cover 212 in the cover rack 120. In someimplementations, the reticle transport device 118 moves the reticle 216and the inner baseplate 214 upward so that the inner cover 212 ispositioned over and on the inner baseplate 214 such that the reticle 216is enclosed in an inner space (e.g., the inner space 302 and/or 402)formed between the inner cover 212 and the inner baseplate 214. In someimplementations, the inner cover 212 is lowered onto the inner baseplate214 such that the reticle 216 is enclosed in the inner space formedbetween the inner cover 212 and the inner baseplate 214.

As shown in FIG. 5F, the reticle transport device 118 may position theinner cover 212 and the inner baseplate 214 (with the reticle 216enclosed therein) in front of the load lock chamber 110. As shown inFIG. 5G, the reticle transport device 118 may extend such that the innercover 212 and the inner baseplate 214 (with the reticle 216 enclosedtherein) are positioned in the load lock chamber 110 in preparation forpassing the inner cover 212 and the inner baseplate 214 (with thereticle 216 enclosed therein) to the reticle transport device 114.

As shown in FIG. 5H, the reticle transport device 114 may retrieve theinner cover 212 and the inner baseplate 214 (with the reticle 216enclosed therein) from the reticle transport device 118. As shown inFIG. 5I, the reticle transport device 114 may retract the inner cover212 and the inner baseplate 214 (with the reticle 216 enclosed therein)from the load lock chamber 110 and into the chamber 112 of the interfacetool 108.

As shown in FIG. 5J, the reticle transport device 114 may extend theinner cover 212 and the inner baseplate 214 (with the reticle 216enclosed therein) out of the chamber 112 and onto the lower shell 206 ofthe reticle carrier 106. The lower shell 206 may be positioned on theload port 104 in preparation for receiving the inner cover 212 and theinner baseplate 214 (with the reticle 216 enclosed therein). As shown inFIG. 5K, the upper shell 204 may be placed onto the lower shell 206 suchthat the inner cover 212 and the inner baseplate 214 (with the reticle216 enclosed therein) are positioned in the inner space 210 formed bythe upper shell 204 and the lower shell 206. Accordingly, an OHT vehicleor another type of transport device may retrieve the reticle carrier 106from the load port 104 and may transport the reticle carrier 106 toanother location such as a reticle storage system.

As indicated above, FIGS. 5A-5K are provided an example. Other examplesmay differ from what is described with regard to FIGS. 5A-5K.

FIG. 6 is a diagram of example components of a device 600. In someimplementations, the exposure tool 102, the load port 104, the interfacetool 108, the reticle transport device 114, and/or the reticle transportdevice 118 may include one or more devices 600 and/or one or morecomponents of device 600. As shown in FIG. 6 , device 600 may include abus 610, a processor 620, a memory 630, a storage component 640, aninput component 650, an output component 660, and a communicationcomponent 670.

Bus 610 includes a component that enables wired and/or wirelesscommunication among the components of device 600. Processor 620 includesa central processing unit, a graphics processing unit, a microprocessor,a controller, a microcontroller, a digital signal processor, afield-programmable gate array, an application-specific integratedcircuit, and/or another type of processing component. Processor 620 isimplemented in hardware, firmware, or a combination of hardware andsoftware. In some implementations, processor 620 includes one or moreprocessors capable of being programmed to perform a function. Memory 630includes a random access memory, a read only memory, and/or another typeof memory (e.g., a flash memory, a magnetic memory, and/or an opticalmemory).

Storage component 640 stores information and/or software related to theoperation of device 600. For example, storage component 640 may includea hard disk drive, a magnetic disk drive, an optical disk drive, a solidstate disk drive, a compact disc, a digital versatile disc, and/oranother type of non-transitory computer-readable medium. Input component650 enables device 600 to receive input, such as user input and/orsensed inputs. For example, input component 650 may include a touchscreen, a keyboard, a keypad, a mouse, a button, a microphone, a switch,a sensor, a global positioning system component, an accelerometer, agyroscope, and/or an actuator. Output component 660 enables device 600to provide output, such as via a display, a speaker, and/or one or morelight-emitting diodes. Communication component 670 enables device 600 tocommunicate with other devices, such as via a wired connection and/or awireless connection. For example, communication component 670 mayinclude a receiver, a transmitter, a transceiver, a modem, a networkinterface card, and/or an antenna.

Device 600 may perform one or more processes described herein. Forexample, a non-transitory computer-readable medium (e.g., memory 630and/or storage component 640) may store a set of instructions (e.g., oneor more instructions, code, software code, and/or program code) forexecution by processor 620. Processor 620 may execute the set ofinstructions to perform one or more processes described herein. In someimplementations, execution of the set of instructions, by one or moreprocessors 620, causes the one or more processors 620 and/or the device600 to perform one or more processes described herein. In someimplementations, hardwired circuitry may be used instead of or incombination with the instructions to perform one or more processesdescribed herein. Thus, implementations described herein are not limitedto any specific combination of hardware circuitry and software.

The number and arrangement of components shown in FIG. 6 are provided asan example. Device 600 may include additional components, fewercomponents, different components, or differently arranged componentsthan those shown in FIG. 6 . Additionally, or alternatively, a set ofcomponents (e.g., one or more components) of device 600 may perform oneor more functions described as being performed by another set ofcomponents of device 600.

FIG. 7 is a flowchart of an example process 700 associated withtransferring a reticle to a reticle carrier described herein. In someimplementations, one or more process blocks of FIG. 7 may be performedby one or more devices and/or tools (e.g., one or more of the exposuretool 102, the load port 104, the interface tool 108, the reticletransport device 114, and/or the reticle transport device 118).Additionally, or alternatively, one or more process blocks of FIG. 7 maybe performed by one or more components of device 600, such as processor620, memory 630, storage component 640, input component 650, outputcomponent 660, and/or communication component 670.

As shown in FIG. 7 , process 700 may include retrieving a reticle froman electrostatic chuck of an exposure tool (block 710). For example, theexposure tool 102 may use the exchanging station 122 to retrieve thereticle 216 from an electrostatic chuck (e.g., the reticle stage 124) ofthe exposure tool 102, as described above.

As further shown in FIG. 7 , process 700 may include positioning thereticle on a plurality of support pins included on a baseplate of areticle carrier (block 720). For example, the exposure tool 102 may usethe exchanging station 122 to position the reticle 216 on a plurality ofsupport pins (e.g., the support pins 304 and/or 404) included on theinner baseplate 214 of the reticle carrier 106, as described above. Insome implementations, a residual charge on the reticle 216 from theelectrostatic chuck is discharged through the plurality of support pinswhen the reticle 216 is positioned on the plurality of support pins. Insome implementations, a distance (d1, d4) between the reticle 216 andthe inner baseplate 214 is configured to prevent attraction of particles314 equal to or greater than a threshold particle size from the innerbaseplate 214 to the reticle 216.

As further shown in FIG. 7 , process 700 may include positioning a coverof the reticle carrier over the reticle such that the reticle isenclosed in an inner space formed between the cover and the baseplate(block 730). For example, the exposure tool 102 may use the reticletransport device 118 to position the inner cover 212 of the reticlecarrier 106 over the reticle 216 such that the reticle 216 is enclosedin an inner space (e.g., the inner space 302 and/or 402) formed betweenthe inner cover 212 and the inner baseplate 214, as described above.

Process 700 may include additional implementations, such as any singleimplementation or any combination of implementations described belowand/or in connection with one or more other processes describedelsewhere herein.

In a first implementation, the distance (d1) between the reticle 216 andthe inner baseplate 214 corresponds to the height (h1) of the pluralityof support pins 304. In a second implementation, alone or in combinationwith the first implementation, the distance (d4) between the reticle 216and the inner baseplate 214 corresponds to a combination of the height(h2) of the plurality of support pins 404 and the depth (d2) of therecessed region 412 in the inner baseplate 214. In a thirdimplementation, alone or in combination with one or more of the firstand second implementations, the distance (d1, d4) between the reticle216 and the inner baseplate 214 is configured to satisfy a dischargerate parameter associated with the reticle 216.

In a fourth implementation, alone or in combination with one or more ofthe first through third implementations, the distance (d1, d4) betweenthe reticle 216 and the inner baseplate 214 is configured to satisfy acapacitance parameter associated with the reticle 216 and the innerbaseplate 214.

Although FIG. 7 shows example blocks of process 700, in someimplementations, process 700 may include additional blocks, fewerblocks, different blocks, or differently arranged blocks than thosedepicted in FIG. 7 . Additionally, or alternatively, two or more of theblocks of process 700 may be performed in parallel.

FIG. 8 is a flowchart of an example process 800 associated with forminga reticle carrier described herein. In some implementations, one or moreprocess blocks of FIG. 8 may be performed by one or more manufacturingdevices and/or systems. Additionally, or alternatively, one or moreprocess blocks of FIG. 8 may be performed by one or more components ofdevice 600, such as processor 620, memory 630, storage component 640,input component 650, output component 660, and/or communicationcomponent 670.

As shown in FIG. 8 , process 800 may include forming a cover of areticle carrier (block 810). For example, the inner cover 212 of thereticle carrier 106 may be formed by casting, molding, machining (e.g.,computer numerical control (CNC) machining or milling), extruding,three-dimensional (3D) printing or another type of additivemanufacturing (e.g., direct metal laser sintering (DMLS)), laser cuttingor water jet cutting, forging, injection, thermoforming, welding, and/oranother manufacturing technique.

As further shown in FIG. 8 , process 800 may include forming a baseplateof the reticle carrier (block 820). For example, the inner baseplate 214of the reticle carrier 106 may be formed by casting, molding, machining(e.g., CNC machining or milling), extruding, 3D printing or another typeof additive manufacturing (e.g., DMLS), laser cutting or water jetcutting, forging, injection, thermoforming, welding, and/or anothermanufacturing technique. In some implementations, the inner cover 212and the inner baseplate 214 are configured to be coupled to form aninner space (e.g., an inner space 302 and/or 402) of the reticle carrier106.

As further shown in FIG. 8 , process 800 may include forming a pluralityof support pins on the baseplate (block 830). For example, the pluralityof support pins (e.g., the support pins 304 and/or 404) on the innerbaseplate 214 may be formed by casting, molding, machining (e.g., CNCmachining or milling), extruding, 3D printing or another type ofadditive manufacturing (e.g., DMLS), laser cutting or water jet cutting,forging, injection, thermoforming, welding, and/or another manufacturingtechnique. In some implementations, at least one of the inner baseplate214 or the plurality of support pins are formed based on a thresholdparticle size to prevent particles 314 equal to or greater than thethreshold particle size from being electrostatically attracted to thereticle 216 that is to be stored in the reticle carrier 106.

Process 800 may include additional implementations, such as any singleimplementation or any combination of implementations described belowand/or in connection with one or more other processes describedelsewhere herein.

In a first implementation, process 800 includes determining (e.g., bythe device 600 using the processor 620) the threshold particle size toprevent the particles 314 equal to or greater than the thresholdparticle size from being electrostatically attracted to the reticle 216.In a second implementation, alone or in combination with the firstimplementation, forming the inner baseplate 214 includes forming therecessed region 412 in a portion of the inner baseplate 214 based on thethreshold particle size to satisfy a capacitance threshold for acapacitance between the inner baseplate 214 and the reticle 216.

In a third implementation, alone or in combination with one or more ofthe first and second implementations, forming the recessed region 412includes forming a first portion of the recessed region 412, that isbetween a first support pin 404 a and a second support pin 404 b of theplurality of support pins 404, to the first width (w1) in a range ofapproximately 130 millimeters to approximately 140 millimeters, andforming a second portion of the recessed region 412, that is not inbetween the first support pin 404 a and the second support pin 404 b, tothe second width (w2) in a range of approximately 140 millimeters toapproximately 155 millimeters.

In a fourth implementation, alone or in combination with one or more ofthe first through third implementations, process 800 includesdetermining (e.g., by the device 600 using the processor 620) anelectrostatic force threshold for attracting particles 314 equal to thethreshold particle size to the reticle 216, determining an electricfield magnitude, for an estimated electric field between the innerbaseplate 214 and the reticle 216, such that the electrostatic forcethreshold is not satisfied, and determining (e.g., by the device 600using the processor 620) a distance (d1, d4) between the inner baseplate214 and the reticle 216 based on the electric field magnitude.

In a fifth implementation, alone or in combination with one or more ofthe first through fourth implementations, forming the inner baseplate214 includes forming the inner baseplate 214 to satisfy the distance(d1, d4). In a sixth implementation, alone or in combination with one ormore of the first through fifth implementations, forming the pluralityof support pins includes forming the plurality of support pins tosatisfy the distance (d1, d4). In a seventh implementation, alone or incombination with one or more of the first through sixth implementations,the distance (d1, d4) is in a range of approximately 1150 microns toapproximately 4000 microns.

Although FIG. 8 shows example blocks of process 800, in someimplementations, process 800 may include additional blocks, fewerblocks, different blocks, or differently arranged blocks than thosedepicted in FIG. 8 . Additionally, or alternatively, two or more of theblocks of process 800 may be performed in parallel.

In this way, a reticle carrier described herein is configured to quicklydischarge the residual charge on a reticle so as to reduce, minimize,and/or prevent particles in the reticle carrier from being attracted toand/or transferred to the reticle. In particular, the reticle carriermay be configured to provide reduced capacitance between an innerbaseplate of the reticle carrier and the reticle. The reduction incapacitance may reduce the resistance-capacitance (RC) time constant fordischarging the residual charge on the reticle, which may increase thedischarge speed for discharging the residual charge through support pinsof the reticle carrier. The increase in discharge speed may reduce thelikelihood that an electrostatic force in the reticle carrier mayattract particles in the reticle carrier to the reticle. This may reducepattern defects transferred to substrates that are patterned using thereticle, may increase semiconductor device manufacturing quality andyield, and may reduce scrap and rework of semiconductor devices and/orwafers.

As described in greater detail above, some implementations describedherein provide a method. The method includes retrieving a reticle froman electrostatic chuck of an exposure tool. The method includespositioning the reticle on a plurality of support pins included on abaseplate of a reticle carrier, where a residual charge on the reticlefrom the electrostatic chuck is discharged through the plurality ofsupport pins when the reticle is positioned on the plurality of supportpins, and where a distance between the reticle and the baseplate isconfigured to prevent attraction of particles equal to or greater than athreshold particle size from the reticle carrier to the reticle. Themethod includes positioning a cover of the reticle carrier over thereticle such that the reticle is enclosed in an inner space formedbetween the cover and the baseplate.

As described in greater detail above, some implementations describedherein provide a reticle carrier. The reticle carrier includes a cover.The reticle carrier includes a baseplate, where the cover and thebaseplate are configured to be coupled to enclose a reticle in an innerspace formed by the cover and the baseplate. The reticle carrierincludes a plurality of support pins, on the baseplate, configured tosupport the reticle in the inner space, where at least one of thebaseplate or the plurality of support pins are configured to facilitatedischarging of a residual charge on the reticle when the reticle isplaced in the reticle carrier.

As described in greater detail above, some implementations describedherein provide a method. The method includes forming a cover of areticle carrier. The method includes forming a baseplate of the reticlecarrier, where the cover and the baseplate are configured to be coupledto form an inner space of the reticle carrier. The method includesforming a plurality of support pins on the baseplate, where at least oneof the baseplate or the plurality of support pins are formed based on athreshold particle size to prevent particles equal to or greater thanthe threshold particle size from being electrostatically attracted to areticle that is to be stored in the reticle carrier.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A method, comprising: retrieving a reticle froman electrostatic chuck of an exposure tool; positioning the reticle on aplurality of support pins included on a baseplate of a reticle carrier,wherein a residual charge on the reticle from the electrostatic chuck isdischarged through the plurality of support pins when the reticle ispositioned on the plurality of support pins, and wherein a distancebetween the reticle and the baseplate is configured to preventattraction of particles equal to or greater than a threshold particlesize from the reticle carrier to the reticle; and positioning a cover ofthe reticle carrier over the reticle such that the reticle is enclosedin an inner space formed between the cover and the baseplate.
 2. Themethod of claim 1, wherein the distance between the reticle and thebaseplate corresponds to a height of the plurality of support pins. 3.The method of claim 1, wherein the distance between the reticle and thebaseplate corresponds to a combination of a height of the plurality ofsupport pins and a depth of a recessed region in the baseplate.
 4. Themethod of claim 1, wherein the distance between the reticle and thebaseplate is configured to satisfy a discharge rate parameter associatedwith the reticle.
 5. The method of claim 1, wherein the distance betweenthe reticle and the baseplate is configured to satisfy a capacitanceparameter associated with the reticle and the baseplate.
 6. A reticlecarrier, comprising: a cover; a baseplate, wherein the cover and thebaseplate are configured to be coupled to enclose a reticle in an innerspace formed by the cover and the baseplate; and a plurality of supportpins, on the baseplate, configured to support the reticle in the innerspace, wherein at least one of the baseplate or the plurality of supportpins are configured to facilitate discharging of a residual charge onthe reticle when the reticle is placed in the reticle carrier.
 7. Thereticle carrier of claim 6, wherein a height the plurality of supportpins is in a range of approximately 1150 microns to approximately 4000microns.
 8. The reticle carrier of claim 6, wherein the baseplateincludes a recessed region in between the plurality of support pins andwithin a perimeter defined by the plurality of support pins; and whereina first distance between the recessed region and a top of a support pinof the plurality of support pins is greater relative to a seconddistance between a non-recessed portion of the baseplate and the top ofthe support pin.
 9. The reticle carrier of claim 8, wherein the firstdistance is in a range of approximately 1150 microns to approximately4000 microns.
 10. The reticle carrier of claim 8, wherein a depth of therecessed region, relative to a top surface of the non-recessed portion,is in a range of approximately 1000 microns to approximately 3500microns.
 11. The reticle carrier of claim 8, wherein a ratio between adepth of the recessed region, relative to a top surface of thenon-recessed portion, and a thickness of the baseplate in the recessedregion is in a range of approximately 0.13 to approximately 0.7.
 12. Thereticle carrier of claim 8, wherein a first width of a first portion ofthe recessed region, that is in between a first support pin and a secondsupport pin of the plurality of support pins, is in a range ofapproximately 130 millimeters to approximately 140 millimeters; andwherein a second width of the recessed region, that is not in betweenthe first support pin and the second support pin, is in a range ofapproximately 140 millimeters to approximately 155 millimeters.
 13. Amethod, comprising: forming a cover of a reticle carrier; forming abaseplate of the reticle carrier, wherein the cover and the baseplateare configured to be coupled to form an inner space of the reticlecarrier; and forming a plurality of support pins on the baseplate,wherein at least one of the baseplate or the plurality of support pinsare formed based on a threshold particle size to prevent particles equalto or greater than the threshold particle size from beingelectrostatically attracted to a reticle that is to be stored in thereticle carrier.
 14. The method of claim 13, further comprising:determining the threshold particle size to prevent the particles equalto or greater than the threshold particle size from beingelectrostatically attracted to the reticle.
 15. The method of claim 13,wherein forming the baseplate comprises: forming a recessed region in aportion of the baseplate based on the threshold particle size to satisfya capacitance threshold for a capacitance between the baseplate and thereticle.
 16. The method of claim 15, wherein forming the recessed regioncomprises: forming a first portion of the recessed region, that isbetween a first support pin and a second support pin of the plurality ofsupport pins, to a first width in a range of approximately 130millimeters to approximately 140 millimeters; and forming a secondportion of the recessed region, that is not in between the first supportpin and the second support pin, to a second width in a range ofapproximately 140 millimeters to approximately 155 millimeters.
 17. Themethod of claim 13, further comprising: determining an electrostaticforce threshold for attracting particles equal to the threshold particlesize to a reticle that is to be stored in the reticle carrier;determining an electric field magnitude, for an estimated electric fieldbetween the baseplate and the reticle, such that the electrostatic forcethreshold is not satisfied; and determining a distance between thebaseplate and the reticle based on the electric field magnitude.
 18. Themethod of claim 17, wherein forming the baseplate comprises: forming thebaseplate to satisfy the distance.
 19. The method of claim 17, whereinforming the plurality of support pins comprises: forming the pluralityof support pins to satisfy the distance.
 20. The method of claim 17,wherein the distance is in a range of approximately 1150 microns toapproximately 4000 microns.